Computer systems typically comprise a combination of computer programs and hardware, such as semiconductors, transistors, chips, circuit boards, storage devices, and processors. The computer programs are stored in the storage devices and are executed by the processors.
One use of computer systems is in cloud computing, in which shared resources, such as computer programs and data stored on computer servers organized as members of a cloud are provided to client computers and other devices on-demand, analogous to a public utility, such as an electricity or telephone company. The cloud typically has multiple computer servers called nodes, which are managed as a group and which share similar properties. The similar properties of nodes within a cloud allow tasks, which need to be repeated on many nodes, such as installing or deploying programs, often called images, to be applied to a group of nodes. Similar properties of nodes within a cloud also allow images to be installed or deployed to any node within a cloud or moved between nodes in a cloud without modifying the image.